Study provides evidence that the sea level rise is real and accelerating

This article from From DW (13 February 2018) concerns the release of the findings of a study by the National Academy of Sciences (PNAS), which is based in the United States. This adds to the mountain of evidence that shows the planet is warming. The co-authors on the study came from the University of South Florida, NASA Goddard Space Flight Center, Old Dominion University and the National Center for Atmospheric Research.

A new report in the US-based Proceedings of the National Academy of Sciences (PNAS) journal released Monday, says sea level rise is accelerating and could reach 66 centimeters (26 inches) by the end of the century.

The projected rise is in line with UN estimates and would be enough to cause significant problems for coastal cities.

According to the report, the past annual rate of sea level rise — about 3 millimeters (.1 inch) per year — may more than triple, to 10 millimeters per year by 2100.

“This acceleration, driven mainly by accelerated melting in Greenland and Antarctica, has the potential to double the total sea level rise by 2100 as compared to projections that assume a constant rate — to more than 60 centimeters instead of about 30,” said the author of the study, Steve Nerem.

Polar ice caps are melting

“And this is almost certainly a conservative estimate,” added Nerem, who is a professor of aerospace engineering sciences at the University of Colorado in Boulder.

The report, which is based on 25 years of satellite data, said the findings were “roughly in agreement with the Intergovernmental Panel on Climate Change’s 5th Assessment Report (AR5) model projections.”

Anny Cazenave, director of earth science at the International Space Science Institute in France, said sea level rise was a better gauge of climate change in action than temperature. Cazenave, who is one of the pioneers of space-based sea level research, edited the study.

Climate change leads to rising sea levels in two ways. First, higher concentrations of greenhouse gases in the atmosphere boost the temperature of water and warm water expands.

The burning of fossil fuels has been linked to rising sea levels

Nerem said thermal expansion of the oceans had already contributed to about half of the 7 centimeters of average global sea level rise in the past quarter century.

Second, ocean levels rise with the increasing flow of water from rapidly melting ice at the poles.

Global sea levels were stable for about 3,000 years, said climate scientist Stefan Rahmstorf, of the Potsdam Institute in Germany. It was in the 20th century that they started rising and then accelerated due to global warming caused by the greenhouse gas emissions through burning fuels like coal, oil and natural gas. Rahmstorf wasn’t part of the study.

“This study highlights the important role that can be played by satellite records in validating climate model projections,” said a co-author of the study, John Fasullo, a climate scientist at the National Center for Atmospheric Research.

Unprecedented heat waves swept across the globe in 2017, leading to droughts, wildfires and even deaths. Australia started the year with temperatures near 50 degrees Celsius (122 Fahrenheit), the “Lucifer” heat wave brought the mercury above 40 degrees Celsius throughout Southern Europe in July and August and scorching heat hit India’s most vulnerable people. Get ready for next summer…

Unprecedented heat waves swept across the globe in 2017, leading to droughts, wildfires and even deaths. Australia started the year with temperatures near 50 degrees Celsius (122 Fahrenheit), the “Lucifer” heat wave brought the mercury above 40 degrees Celsius throughout Southern Europe in July and August and scorching heat hit India’s most vulnerable people. Get ready for next summer…